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08-30-2012, 06:00 PM #1
Lists of why maintenance is required (item specific).
I was thinking today, how many times people ignore the maintenance schedules for their vehicles. I thought I'd start a thread identifying specific maintenance items, and the REASON the periodic maintenance is critical. If you have others, post them, and I'll try to keep up the verified reasons in this main post.
1) Radiator fluid - Ethylene Glycol and Propylene Glycol actually don't deteriorate, but the additives get consumed. Basically, radiator fluid protects your engine by allowing heat to be transferred away from the very high temperature combustion chambers. Unfortunately, the properties of the base fluid are corrosive to some degree, and additives are included to protect your engine. For example, the "pink" fluid found in GM vehicles has a long lifespan, but not indefinite. The radiator fluid is actually corrosive to aluminum (think about how many aluminum parts this comes into contact with), and failure to replace the metal protecting additives through fluid exchange results in degraded gasket seals, and leaks. Also, 50% of the fluid is WATER. Water, alone isn't corrosive, but oxidation of parts can occur. Additionally, be sure to use distilled water, to avoid depositing minerals (which impede fluid flow, causing higher temps). There are a few other reasons to replace it as well, but these are the major ones. Follow your maintenance schedule, and if it's been many many years since you've changed it, you'll probably find a fresh batch of fluid will result in lower temps due to better flow (gunky radiator fluid doesn’t move through the system as well. This is also a reason a radiator flush is sometimes a good idea (it helps remove blockages). While you’re not likely to restore your system with a radiator fluid change, at the very least, you're stopping the progression of deterioration that may have already started. Change on schedule!
2) Engine Oil - Probably a million sites and as many opinions around on this one. A quick summary is that oil breaks down due to friction heat, and additive consumption (such as detergents). Oil is designed to suspend particles that would otherwise gunk up or damage your engine. Larger particles are removed from your oil by the oil filter. The small particles in the oil result from blow-by (fuel, vapors, carbon, etc), and from break-down. Dirty oil is doing it's job, BUT it has a saturation point. Oil can only suspend so many particles before they simply stick in your engine. Also, oil has detergents that sop up broken down oil (suspending the particles in the oil, as well). When your oil breaks down faster than the detergents work, you get sludge (simplified view, but it works for this purpose). Regular changing of the oil removes broken down, contaminated oil, and restores the detergents required to keep your engine's internal components clean. Because modern oils have detergents, they’ll even clean out gunk to some degree. Additionally, your motor oil’s capacity to “do the job” is not measured in miles or time (although both can be used as guides for change intervals). Follow your manufacturer’s recommended oil change cycles. Changing sooner is generally not necessary, as oil’s capacity to protect your engine under normal and severe conditions is accounted for in the maintenance schedule.
3) Engine Oil Filter - This filter removes larger particles from suspension in your oil. Good filters have lots of pleats and may filter smaller particles. Cheap filters will have fewer pleats. Removal of particles and material that could damage your engine is the filter's job. CAUTION: Adding engine cleaners, flushes, etc. may very quickly fill up your oil filter. If this happens the by-pass valve engages, and you're essentially circulating junk through your engine. This is also why you should replace the filter when you change your oil. If you have a “full” filter, particles that would otherwise be removed are now circulating in your system potentially doing damage.
4) Transmission Fluid. Transmission fluid breaks down over time due to heat exposure. The periodic and average temperature of transmission fluid over the lifespan determines the actual breakdown speed. Overheated transmissions actually turn fluid into a sticky varnish (depending on the fluid type), often called “Burning the fluid.” As long as you have not “burned” the transmission fluid, changing a part of the fluid actually extends the life of all of the fluid. Most manufacturer recommendations to change fluid by dropping the pan only results in a portion of the fluid being exchanged. This is normal and is accounted for in the manufacturer’s recommended interval. Failure to partially replace the fluid regularly can be mitigated, to some extent with full fluid flushes, though often, a critical aspect (the filter) is ignored. Do so at your own peril.
5) Transmission Filter – This small filter, actually pulls floating bits and pieces from wear and tear in your transmission and torque converter, out of fluid suspension. Just like dirt on your paint can cause scratches when you rub it, particles in the transmission fluid can quickly wear out clutches and other tight tolerance parts. If your transmission filter is clogged, doing a “transmission flush” isn’t going to change the fact that any new particles are going to continue damaging your transmission. Be sure to follow the manufacturer’s recommended schedule. Like an oil filter, this is an integral part in the protection of very sensitive components.
6) Break fluid, power steering fluid, clutch reservoir fluid. These fluids aren’t exposed to sheer forces, which would cause breakdown, but they can become contaminated from particles or wear of parts. Over time, these fluids get dirty. Dirt in the lines makes its way down into the components these hydraulic systems support. Dirt is grit. Grit destroys. Most manufacturers recommend partial replacement periodically to extend the life of your system.
7) Differential fluids – these fluids are of a higher viscosity. Basically, the weight of a fluid (such as 30 weight, or 75 weight) is an oil GRADE (nothing to do with specific gravity, for the science folks out there). The test, simply described, is like this. Take a specified amount of the fluid and allow it to pour through specifically sized holes at a specific temperature. Measure how many seconds it takes for the fluid to go through the holes. 30w oil takes 30 seconds in that test. 75w oil takes 75 seconds (indicating it’s “thicker). 20w oil takes 20 seconds, and so on. Oil thickens when it’s cooler, btw, which is why the temp is specified. Anyhow, differential and gear box oils use these thick, or heavy viscosity oils to protect heavy duty gears that are meshing, from damage. This stuff needs to be thick enough to protect from the grinding. Change according to manufacturer’s instructions OR… when you get water in your differential or gearbox. Water destroys the viscosity and may also cause frothing (air in the oil). Water and air do not make great lubricants, especially in the high friction environment of your differential or gearbox. Frothing also occurs when you overfill, hence the reason to make sure you’re not doing that, either! Heavy duty use (such as spinning a single wheel for 5 minutes trying to get out of a hole) may break-down the oil more rapidly, as well. Oil that is deteriorated from overheating or sheer damage doesn’t protect as well as the fresh stuff. Change on schedule!
Last edited by Skippy; 08-30-2012 at 10:46 PM.2006 Vortec Max 1500
-Custom Tune (389HP 440 Ft/lbs Trq - Dyno'd) | Volant CAI | Magnaflow Dual-in/out Exhaust w/3" stainless pipe tips | Fully Built Transmission w/ Red Eagle Clutches & Kolene Steels w/ Corvette Servos and Stage2 Shift Kit | 35K Tranny Cooler | Mobil 1 | Royal Purple Rear Diff
-Spray-in Bed Liner
-Premium Sound w/lifetime Satellite Radio | Leather | Sunroof | Heated Seats
-Limbstriping from USING the truck (those are badges of honor)
08-30-2012, 07:22 PM #2
8) Transfer Case (aka: gear box, transfer box) – The fluid in this component largely depends on the application. Fluids range from heavy viscosity gear oil to common transmission fluid, as well as specialized applications. It is also common to have color additives in this fluid to help differentiate from other leaks of similar fluid types. As with the differential, fluid contamination is a result of heat and friction breakdown, as well as particle wear from the components. Unlike engine oil, no blow-by is anticipated in this fluid. Discoloration will be due to heat damage and wear. As with any lubricant protecting gearing, the fluid’s ability to protect the component will degrade with use. In many “all time 4x4” or “electronically engaged” applications, the gearing may be in use, even though it is not directly connected to the driveline. Manufacturer recommended intervals help protect from gear failure. As with differentials if you’ve fully submerged the transfer case, water contamination is likely, and replacement is recommended to prevent fluid failure.
9) Spark plugs – Spark plugs operate by allowing a high voltage current to jump a gap. The central electrode (commonly called the “post” and the lateral electrode (sometimes referred to as the “arm) allow the voltage spark to jump from one electrode to the other. The gap jumping current is exposed to a fuel/air mixture causing ignition of the mixture and combustion in the engine. The spark plug gap distance determines the amount of voltage required to create an electrical spark, as well as determines how much fuel/air is exposed to the spark. Over the life of a spark plug, as the gap increases an additional 20,00 volts may be required to jump the gap! As long as the voltage enables the spark, no misfires occur, though weak sparks may result in incomplete combustion due to timing of the ignition. The metal tip of the spark plug post is exposed to extremely high voltages and heat. The voltage and heat wear down the electrodes during use. The type of metal used on the electrodes determine the wear time. As the electrodes wear down, more voltage is required to allow the spark to jump the gap. Oil, fuel, and carbon can create fouling that prevents a clean spark. Eventually, the spark does not reliably transfer from one electrode to another, and misfires occur. Single, erratic misfires commonly will not create engine codes. By the time your engine is producing a code, the problem is severe. Replacement of worn plugs will commonly create an immediate “power gain” that is noticeable to the driver. This is true, whether it is an expensive long life plug, or one made of softer metals. Replacement of plugs at the scheduled maintenance time will prevent erratic combustion, and may also prevent more costly engine and catalytic convertor damage. Clean sparking plugs also may contribute to restored power and mileage.
10) Spark plug wires – Most spark plug wires aren’t wires at all! In fact, they are made of highly conductive materials, such as carbon fiber, because of the reduced electrical interference (very important in electronic injection vehicles). The “wires” (or electrically conductive core) are wrapped in insulation and silicone to prevent voltage seeping or arcing from the core to the engine block. Over time, the silicone and insulation develops microscopic cracks (typically not visible to the naked eye) that prevent the full voltage of electricity from reaching the spark plug. Replacement of the plug wires at the time of spark plug replacement helps prevent erratic, difficult to diagnose engine behavior, as well as ensures a strong delivery of voltage to the plug.
11) Fuel Filter - The fuel filter filters out contaminants, deposits, floating varnish, gums and other debris drawn into the fuel lines. The filter prevents this debris from becoming lodged in the main lines or fuel rails and prevents the particles from lodging in the fuel injector ports, degrading performance. Over time, the fuel filter clogs and will slow the fuel delivery to the fuel rails. Clogged filters create pressure behind the filter but actually slow the pass-through of fuel to the fuel lines (resulting in low pressure at the fuel rails or injectors). Some GM vehicles only filter the fuel at the fuel pump (located in the fuel tank), while others have in-line filters. In-tank fuel filters are commonly considered “lifetime service” items, though replacement is possible if the fuel tank assembly is removed. In-line filters are more easily accessible, though may require special tools for removal (available at automotive stores or on-line). Fuel filter replacement is generally recommended every 15,000 miles, though service intervals may vary. Replacement of fuel filters may restore performance lost due to inadequate fuel pressure.
12) Air Filter – Air filters prevent abrasive particles from entering the intake and being drawn into the combustion chamber. Air filters clog, over time, and according to the road conditions (e.g. dusty environments clog filters faster) While it is rare for an air filter to actually prevent the operation of modern vehicle if severely clogged (airflow sensors help compensate by provided data to the engine to draw more air, increasing the negative pressure drawing air through the filter), clean filters ensure maximum performance of the engine by allowing substantial amounts of clean air to be drawn into the intake. While mileage gains are generally imperceptible, throttle response and restored power result from replacing a poor condition filter.
Last edited by Skippy; 08-30-2012 at 11:15 PM.
08-30-2012, 07:27 PM #3
The transfer case uses transmission fluid usually.
Also thanks for putting a thread like this out there.
1996 Chevy Tahoe LT 5.7L V8 4X4 202,000+ miles. Built proudly at Janesville Assembly in Janesville, Wisconsin
Basic mods: Lights all over, bunch of electrical work, and a couple cooling mods.
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08-30-2012, 07:49 PM #4
08-30-2012, 07:53 PM #5
My truck says to use GM Dextron III or superseding fluid. Just saying that's what it says in my manual.
08-30-2012, 08:31 PM #6
GM has probably tried to introduce a new colour so you can detect a leak. Probably the same thing with different colour.
08-30-2012, 09:02 PM #7
Yah probably, also it says on the bottle its for automatic transfer cases not ones like mine which you need to manually shift it, obviously via manual shift lever or electronic shifted.
08-30-2012, 10:04 PM #8
All excellent points. I've decided to disengage the differential from the gearbox to add clarity. Same reasoning applies for "why" you'd want to do maintenance though!
10-04-2012, 07:33 AM #9
One thing that is always overlooked is routine tire pressure and tread wear monitoring. Just look at peoples' tires the next time you walk through a parking lot...there will always be completely bald tires, brand new tires with one of the four all but flat, tires with obvious signs of imminent failure, etc..
Not to mention safety items...seat belts should be inspected for abrasion, windshield wipers should be replaced routinely, lights should be checked once and a while, etc..
10-04-2012, 11:20 AM #10
These all can vary and have to may variables to predict intervals yes they are important, but not predictable.
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